Exhaust particulate filter systems are one of many types of emission control technologies that lower particulate matter emissions. Typically, an exhaust particulate filter system includes a housing containing filters. The filters include filter walls that are arranged in parallel with spaces in between. The spaces between the filter walls are closed at every alternate end. Exhaust gases that enter the filter assembly through an opening must pass through filter walls in order to exit the filter assembly. Exhaust matter such as soot and ash that is unable to pass through walls is prevented from exiting the filter assembly.
By trapping exhaust particulate matter as the exhaust gases pass through the filter, exhaust particulate filter systems are able to substantially reduce particulate matter emissions and assist in complying with increasingly stringent emissions standards. While the filter assemblies are generally effective and easy to maintain, they require periodic cleaning, for example at 5000 hours.
U.S. Pat. No. 5,390,492 describes a system in which an incineration chamber is provided downstream of the particulates dislodged from the particulate trap during regeneration thereof by a pulse of compressed air. During regeneration, a valve between the particulate trap and the incineration chamber opens to allow the air and entrained particles to pass into the incineration chamber. A secondary filter is mounted within the incineration chamber to allow passage of the regeneration air therethrough, but prevent passage of the particulates, whereby the particulates are retained in the incineration chamber. A heater in the incineration chamber is periodically activated to burn the particulates collected in the trap. The oxidation products may be released or may be returned to the engine intake in an exhaust gas recirculation system.